The present invention relates to a transferring and molding apparatus for transferring an image or pattern printed in advance on an elongate transfer film onto a molded article, and more particularly to a transferring and molding apparatus in which the transfer film is introduced and sandwiched between a stationary mold member and a movable mold member in an injection mold, thereby transferring the image or the pattern on the transfer film onto the molded article while an injection molding operation is conducted.
A transferring and molding apparatus of this type is disclosed in, for example, Japanese Patent Publication No. 60-59128. Such transferring and molding apparatus comprises a frame mounted on a movable base in an injection mold and movable in a width direction of the transfer film, a width direction moving device for moving the frame to a certain position in the width direction, a feed roller and a tension roller provided on the frame, a longitudinal direction moving device for moving the transfer film in a longitudinal direction by rotating the feed roller, and longitudinal direction and width direction sensors for detecting respective longitudinal direction and width direction marks on the transfer film. In the longitudinal direction moving device, the transfer film is fed at a high speed to a predetermined position immediately before a stop position in the longitudinal direction. When the longitudinal direction sensor detects that the transfer film reaches the predetermined position, the feeding speed is switched to a low speed. Thereafter, when the longitudinal direction sensor detects that the transfer film reaches the stop position, the longitudinal direction moving device is stopped and the transfer film accordingly also is stopped.
Accordingly, in such transferring and molding apparatus, if the longitudinal direction sensor is accurately positionally adjusted so that a reference line of the article molding portion of the mold and a reference line of the transfer film are aligned within an allowable margin of error, the image or pattern can be transferred onto the surface of the molded article with increased accuracy.
However, the transfer film is a continuous elongate roll of film, and the relative position between the image or pattern printed in advance on the transfer film and the longitudinal direction mark is different for different manufacturing lots of the transfer film. Further, if the molded articles are changed and the transfer films to be employed are different types, each relative position between the image or pattern on the transfer film and the longitudinal direction mark is different depending on the type of transfer film.
Therefore, in the conventional transferring and molding apparatus in which when the longitudinal direction sensor detects that the longitudinal direction mark reaches the stop position and the longitudinal direction moving device is stopped, when a different manufacturing lot of the transfer film is used upon replacing the supply drum, or when the molded article is changed, the position of the longitudinal direction sensor again must be accurately adjusted. However, since such position adjustment of the longitudinal direction sensor must be effected by moving the longitudinal sensor little by little while repeating injection molding trials, such adjustment operation is extremely troublesome and difficult.
Further, there has been proposed another type of transferring and molding apparatus, as disclosed in Japanese Publication No. 63-67456. This transferring and molding apparatus is provided with a clamp member and a clamp receiving member which are disposed at a position where a stationary base and a movable base are in confrontation with each other, and which interpose the transfer film introduced between the stationary mold member and the movable mold member, the clamp member and the clamp receiving member each having a surface parallel to the transfer film. The clamp member is axially movable and can apply pressure to the clamp receiving member by a pressing device. The pressure generated by the pressing device is arranged to be larger than the tension in the transfer film generated at the time when the transfer film is sandwiched in a molding space of the stationary and movable mold members. Therefore, this conventional apparatus is arranged so that the transfer film can be clamped by the clamp member and the clamp receiving member when the mold is closed, before the transfer film is sandwiched in the molding space of the stationary and movable mold members, to thus restrain the transfer film firmly by the pressing device. Accordingly, with this clamped state, even if the transfer film is sandwiched in the molding space of the stationary and movable mold members, since the restraining force of the pressing device is larger than the tension generated in the transfer film, the transfer film can be prevented from swerving from a regular position.
However, in the above conventional apparatus, since the transfer film is sandwiched in the molding space of the stationary and movable mold members while the transfer film is firmly clamped by the clamp member and the clamp receiving member, excess tension is generated in the transfer film to thus cause deformation such as elongation. Accordingly, the image or pattern on the molded article may be distorted and impaired.